Conducting polymer based micro sensors will be constructed for the determination of nitric oxide, glucose, alcohol etc. Such conducting polymers as polymetallophthalocyanines (PmePc) and polymetallophorphirins (PmePr), which can catalize the oxidation of compounds including NO, NADH, H2O2 etc., will be electro-chemically deposited on the surface of carbon fibers (or micro carbon disk electrodes) used as a base electrode. The cation exchanger Nafion film will be formed on the PmePc (or PmePr) coated carbon fiber (or disk) electrode in order to discriminate anionic species which tend to behave as interferant. The characterization and calibration of these micro sensors will be carried out by cyclic voltammetry (CV), differential pulse voltammetry (DPV), amperometry, chromoamperometry, differential pulse amperometry (DPA) etc. The nitric oxide sensors will be used in vivo to measure the basal NO tone as well as stimulated and inhibited NO tone in the aorta and renal arteries of rats. These experiments will be related to NO production (or inhibition) associated with chronic renal failure, aging, cyclosporine nephrotoxicity etc. We also plan to construct electrochemical amine sensors which are based on tryptophan tryptophylquinone (TTQ)-containing quinoproteins such as methylamine dehydrogenase (MADH) and aromatic amine dehydrogenase (AADH). For this type of amine sensor, mediators such as tetracyanoquinodimethane (TCNQ) will be absorbed to the surface of carbon disk electrode before amine dehydrogenase enzymes are incorporated onto the surface of electrodes. These sensors will be characterized for the determination of dopamine, histamine, and other primary aliphatic and aromatic amines, etc. by using amperometry.